Changing Water

[pjjp21]

When changing spa water is it ok to use water from the hot water heater, just wondering if it would be a little easier.

john

[Steve]

When changing spa water is it ok to use water from the hot water heater, just wondering if it would be a little easier.

john

Not sure what you mean by "easier"? The advantage would be that the tub would reach temperature quicker, but that's about it. Not really worth it IMO.

Steve

[Electro]

pjjp21,

Thanks for this topic.

I would like to expand it slightly, if that's all right with you.  I have considered filling and draining the water with every use to avoid dealing with chemicals and such.  Even at fairly high water costs, say $2.50 per thousand gallons and adding sewer costs at the same rate, a 500 gallon tub would only cost $2.50 for the water.  Heating it would add about $2.00, if a 6 kW heater operated continuously for 3 1/3 hours and electricity cost 10 cents per kwh.  I feel these numbers are conservative and the likely cost to fill is closer to $3.00 total.  This cost would be partially offset by not using all the normal chemicals.

Would it be necessary to add some minimal chemicals?

What do folks think of this idea?

Electro

[wmccall]

When changing spa water is it ok to use water from the hot water heater, just wondering if it would be a little easier.

john

By easier I assume you are talking about the spa heating up quicker. How big is your water heater? How many gallons is the tub?   In my case we would be talking 40 gallons vs 425.  I don't have a formula, but I'm guessing that when the tub is filled  that it would be less than 1 degree warmer than if you just used the cold for the entire fill.

[Starlight]

pjjp21,

 I have considered filling and draining the water with every use to avoid dealing with chemicals and such. ...

What do folks think of this idea?

Electro

Hi Electro,

It seems to me that the PITA factor of having to plan in advance when you wanted to use the spa, fill, wait hours for the water temp to rise, use, then drain would get old very quickly.  Then there are the issues of leaving pump seal, etc. dry, and dealing with air locks in the lines.  May I ask why you are trying to avoid some form of sanitizers?  Your previous posts indicate plenty of experience maintaining pool water.

Starlight

[Electro]

Starlight,

I like to reassess things, especially those for which I have substantial experience.

Small hot tubs, those known as bathroom whirlpool baths, are filled and emptied every time.  These are typically 50 to 100 gallons or so.  I'm questioning why not do the same with tubs of a few hundred gallons.

The topic came up recently when my son, who was on businees travel, stayed in a fairly nice place that had a 350 gallon tub in the room that was for the one night that each occupant stays.

Why not fill and empty every time?

Electro

[superted]

Something to consider when filling a spa from any domestic hot water tank is psuedomonis. I have had customers fill thier spas with thier hot water heaters and introduce the tiny micro organism that was living inside there. In talking to Different Doctors they have told me this is why you are not supposed to drink hot water from the tap. The psuedomonis or "spa bug" as it is often called, rapidly breeds in warm, moist, dark places (covered hot tubs, water heaters) and is very hard to get rid of. It is best to fill with cool water and heat slowly and treat with an epa registered sanitizer to ensure safety.

[Steve]

Never heard that before... Interesting thought...

Steve

[ZzTop]

Something to consider when filling a spa from any domestic hot water tank is psuedomonis. I have had customers fill thier spas with thier hot water heaters and introduce the tiny micro organism that was living inside there. In talking to Different Doctors they have told me this is why you are not supposed to drink hot water from the tap. The psuedomonis or "spa bug" as it is often called, rapidly breeds in warm, moist, dark places (covered hot tubs, water heaters) and is very hard to get rid of. It is best to fill with cool water and heat slowly and treat with an epa registered sanitizer to ensure safety.

I agree.  A sanitizer is EXTREMELY IMPORTANT.  There is NO safe way to get around this.
Spa bug is only one problem, hello Legionaires disease. regards, Zz

[Shut_Down_Stranger]

Something to consider when filling a spa from any domestic hot water tank is psuedomonis. I have had customers fill thier spas with thier hot water heaters and introduce the tiny micro organism that was living inside there. In talking to Different Doctors they have told me this is why you are not supposed to drink hot water from the tap. The psuedomonis or "spa bug" as it is often called, rapidly breeds in warm, moist, dark places (covered hot tubs, water heaters) and is very hard to get rid of. It is best to fill with cool water and heat slowly and treat with an epa registered sanitizer to ensure safety.

The following clarification is offered.

Assuming that you are on a chlorinated/choraminated  water supply and not an individual household well water system, and you use your hot water regularly, typical hot water is not any more dangerous than regular water.

The disinfectant, chlorine, bromine or ozone will quickly disinfect the water and take out pseudomonis and all the other nasties, including legionella, which is somehat unique to a chloraminated water supplies.  This is why it is important to maintain a chlorine or bromine residual in your spa at all times.

In the absence of a disinfectant, microorganisms of all types will grow.  

[pjjp21]

thanks to all for your replies, they were very informative.

[wmccall]

Never heard that before... Interesting thought...

Steve

I've heard of it, but never  name put to it, I've also heard your not supposed to cook with hot water because of additional elements introduced into the water by the waterheater's elements.

[Mark_Vee]

One thing that I like about using my hot tub is not having to plan to use it.  When I am ready to go in all I have to do is open up the cover and hop in.  If I was to drain and fill it each time there would be alot more down time involved and I wouldn't be able to just go in.  Just my 2 cents.

[Brewman]

There should be nothing wrong per se, in filling your spa with water from your water heater tank, after all, you take baths and showers with that water.  
But I can't see an advantage to dumping several hundred gallons of water every time you exit your spa.
Would you refill immediately, in which case you'd need chemicals anyway, to keep the water good until your next use.  Or would you shut down and let sit empty, and refill just before use?
Your home water heater won't be able to keep up with a hot fill, and you'll be adding mostly cold water, which will take hours to heat.  
I'd think that over time, the cost of the water, time, and such would eat away any small savings over having to buy chemicals.  
Not to mention taking away the spa being ready at any time for you to use.
Maybe explore the least expensive chemical routine.  Not sure what that would be, since I use Baquaspa, not the cheapest chemicals on the market.

Brewman

[Spatech_tuo]

There should be nothing wrong per se, in filling your spa with water from your water heater tank, after all, you take baths and showers with that water.  
 But I can't see an advantage to dumping several hundred gallons of water every time you exit your spa.

Brewman

That is out there. I can't imagine why anyone would do that nowadays and I can't believe they'd stick with it as its as inconvenient as it is crazy.